* Refactoring: move sink/source buffering into separate classes.

* Buffer the HashSink.  This speeds up hashing a bit because it
  prevents lots of calls to the hash update functions (e.g. nix-hash
  went from 9.3s to 8.7s of user time on the closure of my
  /var/run/current-system).

src/libstore/remote-store.cc

@@ -374,7 +374,7 @@ Path RemoteStore::importPath(bool requireSignature, Source & source)
     openConnection();
     writeInt(wopImportPath, to);
     /* We ignore requireSignature, since the worker forces it to true
-       anyway. */    
+       anyway. */
     processStderr(0, &source);
     return readStorePath(from);
 }